GNU Radio 2.x: gr_nco.h Source File

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# gr_nco.h

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    00001 /* -*- c++ -*- */
    00002 /*
    00003  * Copyright 2002 Free Software Foundation, Inc.
    00004  *
    00005  * This file is part of GNU Radio
    00006  *
    00007  * GNU Radio is free software; you can redistribute it and/or modify
    00008  * it under the terms of the GNU General Public License as published by
    00009  * the Free Software Foundation; either version 2, or (at your option)
    00010  * any later version.
    00011  *
    00012  * GNU Radio is distributed in the hope that it will be useful,
    00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015  * GNU General Public License for more details.
    00016  *
    00017  * You should have received a copy of the GNU General Public License
    00018  * along with GNU Radio; see the file COPYING.  If not, write to
    00019  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00020  * Boston, MA 02111-1307, USA.
    00021  */
    00022 #ifndef _GR_NCO_H_
    00023 #define _GR_NCO_H_
    00024
    00025
    00026 #include <vector>
    00027 #include <gr_sincos.h>
    00028 #include <cmath>
    00029
    00035 //FIXME  Eventually generalize this to fixed point
    00036
    00037 template<class o_type, class i_type>
    00038 class gr_nco {
    00039 public:
    00040   gr_nco () : phase (0), phase_inc(0) {}
    00041
    00042   virtual ~gr_nco () {}
    00043
    00044   // radians
    00045   void set_phase (float angle) {
    00046     phase = angle;
    00047   }
    00048
    00049   void adjust_phase (float delta_phase) {
    00050     phase += delta_phase;
    00051   }
    00052
    00053
    00054   // angle_rate is in radians / step
    00055   void set_freq (float angle_rate){
    00056     phase_inc = angle_rate;
    00057   }
    00058
    00059   // angle_rate is a delta in radians / step
    00060   void adjust_freq (float delta_angle_rate)
    00061   {
    00062     phase_inc += delta_angle_rate;
    00063   }
    00064
    00065   // increment current phase angle
    00066
    00067   void step ()
    00068   {
    00069     phase += phase_inc;
    00070     if (fabs (phase) > M_PI){
    00071
    00072       while (phase > M_PI)
    00073         phase -= 2*M_PI;
    00074
    00075       while (phase < -M_PI)
    00076         phase += 2*M_PI;
    00077     }
    00078   }
    00079
    00080   void step (int n) { phase += phase_inc * n; }
    00081
    00082   // units are radians / step
    00083   float get_phase () const { return phase; }
    00084   float get_freq () const { return phase_inc; }
    00085
    00086   // compute sin and cos for current phase angle
    00087   void sincos (float *sinx, float *cosx) const;
    00088
    00089   // compute cos or sin for current phase angle
    00090   float cos () const { return std::cos (phase); }
    00091   float sin () const { return std::sin (phase); }
    00092
    00093 protected:
    00094   float phase;
    00095   float phase_inc;
    00096 };
    00097
    00098 template<class o_type, class i_type>
    00099 void
    00100 gr_nco<o_type,i_type>::sincos (float *sinx, float *cosx) const
    00101 {
    00102   gr_sincosf (phase, sinx, cosx);
    00103 }
    00104
    00105 #endif /* _NCO_H_ */